//C06:6.7 truth.c
#include <stdio.h>
int main(void)
{
    int n = 3;
    while(n)
    {
        printf("%2d is true\n", n--);
    }
    printf("%2d is false\n", n);
    n = -3;
    while(n)
    {
        printf("%2d is true\n", n++);
    }
    printf("%2d is false\n", n);
}
